BAKER, G.P.; HACKER, P.M.S. (2005, 1980). Wittgenstein. Undersanding and Meaning. Volume 1 of an Analytical Commentary on Wittgenstein's Philosophical Investigations, Part II - Exegesis §§1-184. Oxford: Blackwell. [Contains on pp. 33-42 an extensive interpretation of the preface, which can be read in connection with the history of the composition of the PI on pp. 1-6.]

BINKLEY, Timothy (1973). Wittgenstein's Language. The Hague: Martinus Nijhoff. [Contains on p. 8 a discussion of the PI preface and on pp. 20-31 discussions of the "landscape" and "album" metaphors.]

HILMY, Stephen S. (1987). The Later Wittgenstein. The Emergence of a New Philosophical Method. Oxford: Basil Blackwell. [Contains on pp. 15-25 a discussion of the PI preface taking into account various prefatory and methodological remarks in the Nachlass.]

MONK, Ray (1990). Ludwig Wittgenstein. The Duty of Genius. London: Jonathan Cape. [Contains on p. 413 references to both the 1938 version and the later version of the PI preface, as well as other relevant notes throughout the book.]